Question about Technics SCEH790 CD Shelf System

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How to avoid drawer not opening in the future tips.

Can unit be safely inspected to check gears & track?
How can danger from laser be reduced?
What is the level of danger from the laser if CD is switched off:

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The taping on top worked best
On instpecting the track no obvious cause of problem seen and understanding of mechanism helps
See how it will go
Thanks
Rosalie

Posted on Jul 18, 2008

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My jvc compact component system cd drawer won't open


The loading belt is broken, or the gears are jammed and locked down, either way a major dis-assembly will be required to attempt repair.

Mar 27, 2012 | JVC Audio Players & Recorders

1 Answer

My cd drawer will not open. It was suggested that a belt was slipping and I take it apart. How do I do this?


To be honest with you...this unit is quite complicated to be user serviceable.When to press the open button for the cd drawer..do you hear the motor running.this unit uses gears to open the drawer.If you can hear the motor..and even if not...the drawer is not opening...please get it serviced by a qualified technician.If you try to repair this yourself..you can easily cause more damage to the unit.....by all means...DO NOT DISASSEMBLE THIS UNIT YOURSELF.I hope this was helpful....

Oct 29, 2010 | JVC MX-K30 CD Shelf System

1 Answer

It doesnt recognise cds


There are a few possible causes. 1. Lens on laser pickups dirty. 2. The belt that closes the drawer also lifts the CD assembly to allow disc to spin. If the belt is loose, drawer may close but not be able to lift CD. Listen to mechanism after drawer closes. Do you hear the disc spinning up? or Do you hear a motor trying and then shutting off? You can also remove the case top and visually check these. 3. The spindle height may have slipped. 4. The focus and tracking may have changed with age. 5. The pickup may be bad. And finally the carriage may be stuck and not moving the Pickup(Laser Assembly) to its start position.

Jul 17, 2009 | JVC MX-D401T Shelf System

1 Answer

Cd disk not turning . takes disk ,lifts disk ,and does not turn or plays cd


There may be a dirty leaf switch under the load tray thats in need of cleaning or the load mech may have slipped a tooth on the gear and may not be full enguaged. Does the laser assembly try to focus on the disc? The lens should move up and down right after loading. If not the unit may think drawer isnt fully closed.

Jul 15, 2009 | Audio Players & Recorders

1 Answer

I have an RCA shelf stereo, model RS2653. My cd player reads the disc's put then it does not play them. The last time I used it all of the items in it worked. Could you please help me to figure out what...


Manually cleaning the lens To locate the laser lens, look around the door or drawer of the DVD player and you will see a small circular disc, which is often called the turntable or disc platter. Right off the edge of the platter you should see a small clear lens. There are some manufacturers that have had problems with the lens, depending on the age of the unit. In these problem players, moving the unit to a different location, turning the unit upside down, or sometimes even without moving the unit, the lens can become detached from the laser assembly and floats around inside the unit. You can re-glue it back with a little crazy glue, BUT it must be perfectly centered, and without getting any glue on it. So, if you don?t see the plastic lens, but instead see the laser pick-up assembly, look around for the lens inside the unit and glue it back on. To clean the lens you must use very little pressure. Take a cotton swab and barely moisten it with plain, non-scented, or oily type alcohol. In a swirling motion, very gently rub the lens until you?ve covered it entirely. Then repeat using the dry end. If the cleaning didn?t help, don?t despair just yet. You can see if there?s a problem elsewhere in the unit by using a few simple tricks and tips. First thing you want to see if the unit?s laser is in good working order. This method isn?t foolproof, but most of the time works admirably. When you insert a disc, see if you can look up underneath where the disc sits on the turntable. Observe the laser lens going up and down. If the lens is trying to focus, that?s good! After a few seconds of the lens trying to focus, the platter should start to spin. On almost every CD/DVD unit I've encountered, the unit won't spin unless the laser has properly focused on the surface of the disc. If the unit spins up and and then shuts down, you should check and make sure the laser pick-up assembly slider mechanism is working without any obstructions and that the small chrome rail that it slides on is slightly greased. Don?t go overboard with the grease though, as too much can cause all sorts of problems. The slider mechanism, depending on the age of the unit and the manufacturer, consists of the small chrome rail, a drive motor, a small gear assembly, and (in some units) a small belt that drives the slider unit via the motor. This small belt causes all sorts of problems. If the belt is broken or slipping, it can cause skipping, dropouts, or simply no start up at all. Also, if the belt breaks in the middle of the disc, the drive mechanism gets hair or dirt wrapped up into the gears, or the pick-up assembly doesn?t return to the start position (called home), the unit will (99% of the time) refuse to release the disc, causing it to become stuck inside the unit. There?s a little micro or leaf type switch located at home position that sometimes gets dirty or breaks and, causing this problem also. If the disc starts to spin slowly and doesn?t come up to speed, the spindle motor that?s attached to the turntable platter is a common problem. There could also be a problem with the spindle motor driver controller IC or the power supply regulator that supplies voltage to the driver IC. If the disc starts to spin and then spins really fast, or stops and starts to spin backwards, your problem is the laser pick-up assembly or the servo control circuit. If you continue to have problems after cleaning and checking the other things listed above, you may have a problem with the player's alignment. Of course, one of the problems you'll face checking alignments on a DVD/CD player is that you?re going to need to use an oscilloscope on most of them. If you have the proper tools and equipment, the first thing to look at is the RF pattern of the unit while its playing. It should be a sharp and clear pattern. If it's dull and smeared, then the laser could be weak. Also, in these units are very critical alignments called the focus/tracking gains and offsets. When these alignments are off, it can often cause intermittent troubles. As the unit ages and parts change value, so do these alignments, and will need to be checked. In my time as service technician repairing DVD/CD players, 65% of the laser pick-up assembles I have tested were good and only needed a small adjustment. Today's technology makes it unfeasible for a shop to hook up a DVD/CD player, and even some recorders, to their equipment and make these adjustments because of the cost involved. Hope this may help; Regards, VOTIT

Jun 08, 2009 | RCA RS2652 Shelf System

1 Answer

CD Player Problems


Manually cleaning the lens
To locate the laser lens, look around the door or drawer of the DVD player and you will see a small circular disc, which is often called the turntable or disc platter. Right off the edge of the platter you should see a small clear lens. There are some manufacturers that have had problems with the lens, depending on the age of the unit. In these problem players, moving the unit to a different location, turning the unit upside down, or sometimes even without moving the unit, the lens can become detached from the laser assembly and floats around inside the unit. You can re-glue it back with a little crazy glue, BUT it must be perfectly centered, and without getting any glue on it. So, if you don’t see the plastic lens, but instead see the laser pick-up assembly, look around for the lens inside the unit and glue it back on.
To clean the lens you must use very little pressure. Take a cotton swab and barely moisten it with plain, non-scented, or oily type alcohol. In a swirling motion, very gently rub the lens until you’ve covered it entirely. Then repeat using the dry end.
If the cleaning didn’t help, don’t despair just yet. You can see if there’s a problem elsewhere in the unit by using a few simple tricks and tips.
First thing you want to see if the unit’s laser is in good working order. This method isn’t foolproof, but most of the time works admirably. When you insert a disc, see if you can look up underneath where the disc sits on the turntable. Observe the laser lens going up and down. If the lens is trying to focus, that’s good! After a few seconds of the lens trying to focus, the platter should start to spin. On almost every CD/DVD unit I've encountered, the unit won't spin unless the laser has properly focused on the surface of the disc. If the unit spins up and and then shuts down, you should check and make sure the laser pick-up assembly slider mechanism is working without any obstructions and that the small chrome rail that it slides on is slightly greased. Don’t go overboard with the grease though, as too much can cause all sorts of problems.
The slider mechanism, depending on the age of the unit and the manufacturer, consists of the small chrome rail, a drive motor, a small gear assembly, and (in some units) a small belt that drives the slider unit via the motor. This small belt causes all sorts of problems. If the belt is broken or slipping, it can cause skipping, dropouts, or simply no start up at all. Also, if the belt breaks in the middle of the disc, the drive mechanism gets hair or dirt wrapped up into the gears, or the pick-up assembly doesn’t return to the start position (called home), the unit will (99% of the time) refuse to release the disc, causing it to become stuck inside the unit. There’s a little micro or leaf type switch located at home position that sometimes gets dirty or breaks and, causing this problem also.
If the disc starts to spin slowly and doesn’t come up to speed, the spindle motor that’s attached to the turntable platter is a common problem. There could also be a problem with the spindle motor driver controller IC or the power supply regulator that supplies voltage to the driver IC. If the disc starts to spin and then spins really fast, or stops and starts to spin backwards, your problem is the laser pick-up assembly or the servo control circuit. If you continue to have problems after cleaning and checking the other things listed above, you may have a problem with the player's alignment. Of course, one of the problems you'll face checking alignments on a DVD/CD player is that you’re going to need to use an oscilloscope on most of them. If you have the proper tools and equipment, the first thing to look at is the RF pattern of the unit while its playing. It should be a sharp and clear pattern. If it's dull and smeared, then the laser could be weak.
Also, in these units are very critical alignments called the focus/tracking gains and offsets. When these alignments are off, it can often cause intermittent troubles. As the unit ages and parts change value, so do these alignments, and will need to be checked. In my time as service technician repairing DVD/CD players, 65% of the laser pick-up assembles I have tested were good and only needed a small adjustment. Today's technology makes it unfeasible for a shop to hook up a DVD/CD player, and even some recorders, to their equipment and make these adjustments because of the cost involved.

Hope this may help;

Regards,
VOTIT

DON'T TO FORGET TO RATE

Aug 17, 2008 | JVC MX-KC58 Shelf System

1 Answer

CD player


Manually cleaning the lens
To locate the laser lens, look around the door or drawer of the DVD player and you will see a small circular disc, which is often called the turntable or disc platter. Right off the edge of the platter you should see a small clear lens. There are some manufacturers that have had problems with the lens, depending on the age of the unit. In these problem players, moving the unit to a different location, turning the unit upside down, or sometimes even without moving the unit, the lens can become detached from the laser assembly and floats around inside the unit. You can re-glue it back with a little crazy glue, BUT it must be perfectly centered, and without getting any glue on it. So, if you don’t see the plastic lens, but instead see the laser pick-up assembly, look around for the lens inside the unit and glue it back on.
To clean the lens you must use very little pressure. Take a cotton swab and barely moisten it with plain, non-scented, or oily type alcohol. In a swirling motion, very gently rub the lens until you’ve covered it entirely. Then repeat using the dry end.
If the cleaning didn’t help, don’t despair just yet. You can see if there’s a problem elsewhere in the unit by using a few simple tricks and tips.
First thing you want to see if the unit’s laser is in good working order. This method isn’t foolproof, but most of the time works admirably. When you insert a disc, see if you can look up underneath where the disc sits on the turntable. Observe the laser lens going up and down. If the lens is trying to focus, that’s good! After a few seconds of the lens trying to focus, the platter should start to spin. On almost every CD/DVD unit I've encountered, the unit won't spin unless the laser has properly focused on the surface of the disc. If the unit spins up and and then shuts down, you should check and make sure the laser pick-up assembly slider mechanism is working without any obstructions and that the small chrome rail that it slides on is slightly greased. Don’t go overboard with the grease though, as too much can cause all sorts of problems.
The slider mechanism, depending on the age of the unit and the manufacturer, consists of the small chrome rail, a drive motor, a small gear assembly, and (in some units) a small belt that drives the slider unit via the motor. This small belt causes all sorts of problems. If the belt is broken or slipping, it can cause skipping, dropouts, or simply no start up at all. Also, if the belt breaks in the middle of the disc, the drive mechanism gets hair or dirt wrapped up into the gears, or the pick-up assembly doesn’t return to the start position (called home), the unit will (99% of the time) refuse to release the disc, causing it to become stuck inside the unit. There’s a little micro or leaf type switch located at home position that sometimes gets dirty or breaks and, causing this problem also.
If the disc starts to spin slowly and doesn’t come up to speed, the spindle motor that’s attached to the turntable platter is a common problem. There could also be a problem with the spindle motor driver controller IC or the power supply regulator that supplies voltage to the driver IC. If the disc starts to spin and then spins really fast, or stops and starts to spin backwards, your problem is the laser pick-up assembly or the servo control circuit. If you continue to have problems after cleaning and checking the other things listed above, you may have a problem with the player's alignment. Of course, one of the problems you'll face checking alignments on a DVD/CD player is that you’re going to need to use an oscilloscope on most of them. If you have the proper tools and equipment, the first thing to look at is the RF pattern of the unit while its playing. It should be a sharp and clear pattern. If it's dull and smeared, then the laser could be weak.
Also, in these units are very critical alignments called the focus/tracking gains and offsets. When these alignments are off, it can often cause intermittent troubles. As the unit ages and parts change value, so do these alignments, and will need to be checked. In my time as service technician repairing DVD/CD players, 65% of the laser pick-up assembles I have tested were good and only needed a small adjustment. Today's technology makes it unfeasible for a shop to hook up a DVD/CD player, and even some recorders, to their equipment and make these adjustments because of the cost involved.

hope this may help;


DON'T FORGET TO RATE;


Regards,
VOTIT

Jul 27, 2008 | Sony MHC-RG20 CD Shelf System

1 Answer

CD PLAYER.SL-PJ26 Drawer does not open


The tray gears are struck or jamed. need to open the unit.

Jul 15, 2008 | Technics SCEH790 CD Shelf System

1 Answer

CD drawer won't open


hi, try opening up the cover lid, and manually give a mild push to the tray, must be some small jam, or the eject belt or gear,.let me know

Dec 28, 2007 | Teac GF-300 CD Shelf System

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